1. Field of the Invention
The present invention relates to a method and system for managing Quality of Service (QoS)-guaranteed multimode fast mobility in wireless networks that is capable of efficiency supporting real-time multimedia services, such as Internet Protocol (IP)-based voice call, video call and video conference, without deterioration of QoS when a mobile host equipped with two or more wireless communication interfaces moves between cells of homogeneous or heterogeneous wireless networks. Here, the “wireless networks” include Wireless Personal Area Networks (WPANs), Wireless Local Area Networks (WLANs), Wireless Metropolitan Area Networks (WMANs) and Wireless Wide Area Networks (WWANs).
2. Description of the Related Art
The art related to the present invention will be described first. A next-generation wireless communication network will be constructed in such a way that WPANs, WLANs and WMANs, which are being developed by the IEEE 802 working group, as well as third-generation (3G) and fourth-generation (4G) wideband WWANs will be interconnected on an all-IP basis. Across these various wireless communication networks, each mobile host will operate in a multimode based on a plurality of different wireless communication interfaces and support IP-based mobile real-time multimedia services such as mobile Voice over IP (VoIP), mobile IPTV and mobile real-time video conference. From the standpoint of a user, although the next-generation wireless communication network has fast packet transmission capability, there is a problem in that a mobile host does not provide a fast mobility management function capable of guaranteeing the provision of real-time multimedia services when the mobile host moves between homogeneous or heterogeneous wireless networks.
The prior art related to the management of mobility when a mobile host moves between cells of various wireless networks will be described next. There is a Generic Access Network (GAN) structure that was proposed by the UMA Forum as the ETSI TS standard in order to perform the mobility management of a dual mode phone that enables switching between a Global System for Mobile communication (GSM) network and an IEEE 802.11 WLAN without disruption of service. Meanwhile, the Internet Multimedia System (IMS) forum has carried out research into a scheme for supporting seamless VoIP in various wired/wireless converged communication networks on the basis of Session Initiation Protocol (SIP). Furthermore, the Fixed Mobile Convergence Alliance (FMCA) announced a technology for enabling interworking between a Bluetooth WPAN and a cellular wireless network. However, the GAN and IMS technologies are technologies for providing seamless IP connection from the standpoint of a service provider, and have problems in that service disruption occurs in the case of the occurrence of change in the IP address of a mobile host and it does not guarantee QoS and does not provide a fast handover function during movement.
In addition to these work, there are Mobile IP (MIP), Fast MIP and Hierarchical MIP developed by IETF, which is an Internet standardization organization, to support IP mobility management, SCTP-ADDIP developed to support mobility management in the transport layer, and SIP developed to support mobility management in the application layer. However, most of the IETF handover international standards do not provide a fast mobility management function of guaranteeing QoS in various heterogeneous wireless networks. Recently, the IETF multi-homing working group has carried out research into a method for improving distributed system service reliability or performance related to a mobile node in the case where the mobile node is equipped with a plurality of different interfaces and has a plurality of temporary IP addresses. However, unlike the research in the IETF multi-homing working group, the present invention enables parallel distributed packet tunnels to be established through an SIP-based Open Mobility Management Server (OMS) at an intermediate location, rather than at end-to-end locations, using a plurality of interfaces and then enables mobility management to be performed therethrough, so that the present invention is different from the research that has been carried out by the IETF multi-homing working group.
Additionally, although the IEEE 802.21 working group developed the Media Independent Handover (MIH) standard interface for enabling interworking between various wireless networks in the data link layer, it does not propose a method for guaranteeing QoS when hosts move.
In conclusion, although many technologies and international standards have been developed up to now, there is no reliable QoS-guaranteed fast wireless network mobility management for guaranteeing seamless mobility to users when mobile hosts move between various wireless networks.